Download or read book Fracture Behavior of Advanced Structural Materials written by Joseph Aaron Lemberg and published by . This book was released on 2011 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: Further development of ultra-high structural applications requires new materials that can withstand the extreme environments found in power-generation turbines. Highly refractory materials capable of high strength at temperatures in excess of 1100°C are either inherently brittle (Al2O3, Si3N4) or cannot survive at such temperatures in oxidizing atmospheres (Mo, Nb). Brittle materials may be toughened with the addition of a more ductile phase. Materials that do not form protective oxide layers can be alloyed with Si to form more protective silicate scales. A problem still remains as to how dissimilar materials like Al2O3 and Si3N4 can be joined. A brief discussion of the fracture behavior of ductile-phase-toughened nanocrystalline Al2O3 and functionally-graded material joints of Al2O3 and Si3N4 will precede an in-depth exploration of fracture in two Mo-Si-B intermetallic alloys. Al2O3-based nanocomposites were fabricated and consolidated via spark plasma sintering. The influence on the fracture behavior of nanocrystalline Al2O3 of single-walled carbon nanotube (SWCNT) and Nb additions were examined by in-situ bend testing within a scanning electron microscope. The addition of 10 vol.% Nb to nanocrystalline Al2O3 provided substantial improvement of fracture toughness (6.1MPa-m1/2)--almost three times that of unalloyed nanocrystalline Al2O3. Observation of cracks emanating from Vickers indents, as well as bend specimen fracture surfaces, reveal the operation of ductile phase toughening in the Nb-Al2O3 nanocomposites. Further addition of 5 vol.% SWCNTs to the 10 vol.% Nb-Al2O3 revealed a more porous structure and less impressive fracture toughness. The SWCNTs, initially added to form uncracked ligament bridges spanning the crack which would carry load and shield the crack tip from the full extent of the remotely-applied load, acted as crack initiation sites and overwhelmed any toughness gains afforded by the ductile Nb grains. Nominally crack-free Al2O3- Si3N4 joints, comprised of 15 layers of gradually differing compositions of Al2O3/Si3N4, have been fabricated using SiAlON polytypoids as functionally graded materials (FGM) bonding layers for high-temperature applications. Using flexural strength tests conducted both at room and at elevated temperatures, the average fracture strength at room temperature was found to be 437 MPa; significantly, this value was unchanged at temperatures up to 1000°C. Scanning electron microscopy (SEM) observations of fracture surfaces indicated the absence of any glassy phase at the triple points. This result was quite contrary to the previously reported 20-layer Al2O3/Si3N4 FGM samples where three-point bend testing revealed severe strength degradation at high temperatures. Consequently, the joining of Al2O3 to Si3N4 using functional gradients of SiAlON polytypoids can markedly improve the suitability of these joints for high-temperature applications. New alloys based on borosilicides of molybdenum have been considered as potential replacements for current Ni-base superalloys, as they show promise as highly oxidation- and creep-resistant materials while still maintaining a moderate level of damage tolerance. Two alloys, each composed of Mo-3Si-1B (wt.%) with nominally similar fine-grained microstructures, have been developed utilizing markedly differing processing routes. Here, we study the influence of processing route on the fracture toughness of alloys containing ~55 vol.% ductile [alpha]-Mo and ~45 vol.% brittle intermetallics (Mo3Si and Mo5SiB2 (T2)). The room-temperature toughness of these two alloys is significantly lower than that previously evaluated coarser-grained Mo-Si-B alloys with similar composition; however at 1300°C, the crack-initiation toughness of the fine- and coarse-grained alloys are nearly identical. At lower temperatures, the current finer-grained materials behave in a brittle manner as the smaller grains do not provide much impediment to crack extension; cracks can advance with minimal deflection thereby limiting any extrinsic toughening. Plastic constraint of ductile [alpha]-Mo grains from the hard intermetallic grains also serves to lower the toughness. At 1300°C, the increased ductility of [alpha]-Mo allows for significant plasticity; the correspondingly much larger contribution from intrinsic toughening results in significantly enhanced toughness, such that the finer grain morphology becomes less important in limiting crack-growth resistance. Optimization of these alloys is still required, however, to tailor their microstructures for the mutually-exclusive requirements of oxidation resistance, creep resistance and damage tolerance.
Download or read book Fracture of Structural Materials written by A. S. Tetelman and published by John Wiley & Sons. This book was released on 1967 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue and Fracture of Traditional and Advanced Structural Alloys written by Filippo Berto and published by MDPI. This book was released on 2021-04-01 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fatigue behavior of traditional and advanced materials is a very relevant topic in different strategic applications impacting and affecting our daily lives. The present Special Issue invites papers to update readers on the state of the art on this important topic. Both review and original manuscripts are welcome. Special attention will be dedicated to innovative materials and innovative manufacturing processes or post-treatments able to improve the fatigue life and reliability of a structural component. Scale effect will be also fully treated focusing on different applications and multiscale approaches aimed at understanding structural integrity under cyclic loadings. This state of the art perspective will help engineers, designers and people from the academy gain an updated view on this very challenging topic which is nowadays very important due to the advances in manufacturing technologies that allow complex new materials to be fabricated.
Download or read book Advanced Structural Materials written by Winston O. Soboyejo and published by CRC Press. This book was released on 2006-12-21 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: A snapshot of the central ideas used to control fracture properties of engineered structural metallic materials, Advanced Structural Materials: Properties, Design Optimization, and Applications illustrates the critical role that advanced structural metallic materials play in aerospace, biomedical, automotive, sporting goods, and other indust
Download or read book Creep and Fracture of Engineering Materials and Structures written by T. Sakuma and published by Trans Tech Publications Ltd. This book was released on 1999-10-12 with total page 888 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume is indexed by Thomson Reuters CPCI-S (WoS). Recent research on the creep and fracture of engineering materials is presented, with particular emphasis being placed on: mechanisms of high-temperature deformation and fracture, materials for high-temperature service, the behavior of single and polycrystals, components and structures, grain boundaries and interfaces, and superplasticity.
Download or read book Advanced Structural Materials III written by Heberto Balmori-Ramírez and published by Trans Tech Publications Ltd. This book was released on 2007-11-15 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: This useful collection presents fascinating reviews, and reports of recent investigations, related to advanced metallic, ceramic and composite structural materials. The topics covered include innovative processing techniques, phase transformations, mechanical properties and explorations of the relationship between processing methods, microstructure and mechanical behavior.
Download or read book Dynamic Fracture Behavior of Structural Materials written by J. H. Giovanola and published by . This book was released on 1986 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents results of a program to improve understanding of dynamic fracture behavior by investigating both crack tip loading conditions and material properties for fracture at high loading rates. A new test procedure, the one-point-bend test was analyzed and further developed the test a wide range of materials at impact loading rates. The test uses inertial loading to load the crack tip and affords an unambiguous measurement of the dynamic initiation toughness. The test's usefulness in producing small controlled increments of crack extension and in crack propagation studies was also demonstrated. Moreover, the concept of inertial loading was extended to study dynamic mixed- mode crack initiation under controlled mixed mode I and II conditions. These new test techniques were used to establish the dynamic fracture behavior of 4340 steel (HRC 50). It was shown that, for loading times to fracture as short as 20 microsecs, no time-modified criterion is necessary to predict crack initiation. The classical fracture criterion equating the applied stress intensity to the dynamic fracture toughness is adequate, provided the dynamically applied stress intensity is correctly evaluated. Under mixed mode I and II loading with (k sub II)/(k sub I) values between 0 and 0.5, it was demonstrated that dynamic crack initiation is essentially controlled by the mode I stress intensity and by the mode I dynamic fracture toughness.
Download or read book Deformation and Fracture Behaviour of Advanced Structural Steels written by Chiradeep Gupta and published by LAP Lambert Academic Publishing. This book was released on 2012-03 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: The manifestations of life limiting phenomena in structural materials largely dictates the technological options which can be implemented in power plants. An understanding of these phenomena are therefore critical to set-up power plants based on sustainable technologies. This monograph compiles the research on the three phenomena that degrade the technological properties of steels used for thermal and nuclear power plants. It is therefore relevant to practicing engineers, material scientists and designers needing to know the effect of dynamic strain aging, ratcheting and creep on low alloyed and heat resistant steels used for pressure boundary applications in nuclear and thermal power plants.
Download or read book Damage and Fracture of Composite Materials and Structures written by Mohd Nasir Tamin and published by Springer Science & Business Media. This book was released on 2012-01-05 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph presents recent research findings on fracture properties and behavior of the composites, and their damage and cracking process under both quasi-static and impact loading conditions. Theoretical treatment, experimental investigation and numerical simulation aspects of the mechanics of composites, including sandwich structures are included.
Download or read book Deformation and Fracture Behaviour of Polymer Materials written by Wolfgang Grellmann and published by Springer. This book was released on 2017-07-12 with total page 537 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the most recent advances in the deformation and fracture behaviour of polymer material. It provides deeper insight into related morphology–property correlations of thermoplastics, elastomers and polymer resins. Each chapter of this book gives a comprehensive review of state-of-the-art methods of materials testing and diagnostics, tailored for plastic pipes, films and adhesive systems as well as elastomeric components and others. The investigation of deformation and fracture behaviour using the experimental methods of fracture mechanics has been the subject of intense research during the last decade. In a systematic manner, modern aspects of fracture mechanics in the industrial application of polymers for bridging basic research and industrial development are illustrated by multifarious examples of innovative materials usage. This book will be of value to scientists, engineers and in polymer materials science.
Download or read book Advanced Fracture Mechanics and Structural Integrity written by Ashok Saxena and published by CRC Press. This book was released on 2019-02-06 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Fracture Mechanics and Structural Integrity is organized to cover quantitative descriptions of crack growth and fracture phenomena. The mechanics of fracture are explained, emphasizing elastic-plastic and time-dependent fracture mechanics. Applications are presented, using examples from power generation, aerospace, marine, and chemical industries, with focus on predicting the remaining life of structural components and advanced testing metods for structural materials. Numerous examples and end-of-chapter problems are provided, along with references to encourage further study.The book is written for use in an advanced graduate course on fracture mechanics or structural integrity.
Download or read book Analysis of Engineering Structures and Material Behavior written by Josip Brnic and published by John Wiley & Sons. This book was released on 2018-01-18 with total page 723 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theoretical and experimental study of the mechanical behavior of structures under load Analysis of Engineering Structures and Material Behavior is a textbook covering introductory and advanced topics in structural analysis. It begins with an introduction to the topic, before covering fundamental concepts of stress, strain and information about mechanical testing of materials. Material behaviors, yield criteria and loads imposed on the engineering elements are also discussed. The book then moves on to cover more advanced areas including relationships between stress and strain, rheological models, creep of metallic materials and fracture mechanics. Finally, the finite element method and its applications are considered. Key features: Covers introductory and advanced topics in structural analysis, including load, stress, strain, creep, fatigue and finite element analysis of structural elements. Includes examples and considers mathematical formulations. A pedagogical approach to the topic. Analysis of Engineering Structures and Material Behavior is suitable as a textbook for structural analysis and mechanics courses in structural, civil and mechanical engineering, as well as a valuable guide for practicing engineers.
Download or read book Thermomechanical Behavior of Advanced Structural Materials written by American Society of Mechanical Engineers. Winter Annual Meeting and published by . This book was released on 1993 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Structural Materials II written by Heberto Balmori-Ramírez and published by Trans Tech Publications Ltd. This book was released on 2006-03-15 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection comprises invited and contributed papers which were presented at the Advanced Structural Materials Symposium held in Cancún, México during the Annual Conference of the Mexican Academy of Materials Science. Volume is indexed by Thomson Reuters CPCI-S (WoS).
Download or read book Fracture of Structural Materials written by and published by . This book was released on 1986 with total page 697 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasticity Damage and Fracture in Advanced Materials written by Holm Altenbach and published by Springer Nature. This book was released on 2019-11-26 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents studies on the plasticity, failure, and damage behavior of materials and structures under monotonic and cyclic loads. Featuring contributions by leading authors from around the globe, it focuses on the description of new effects observed in experiments, such as damage under cyclic loading. It also proposes various simulation models based on different approaches and compares them with tests, taking scaling aspects into account.
Download or read book Application of Fracture Toughness Parameters to Structural Metals written by Metallurgical Society of AIME. Institute of Metals Division. Structural Materials Technical Committee and published by . This book was released on 1966 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:
